84 C4 High Rev
Thread Starter
Intermediate
Joined: Dec 2021
Posts: 38
Likes: 3
From: 10950
84 C4 High Rev
I bought a 1984 C4 before winter started and now its springtime, I am ready to start working on it. My problem right now is I want to pull it in and out of my garage, but I am afraid that breaks will let go and I will drive right thought the wall. I have a high idle of roughly 3k and roughly 2k when I put it in gear. The car has 33k miles on it. What parts should I buy to fix this problem or what can I do to solve the problem. I am assuming its 1 of 2 things or maybe both. please let me know a solution so I can't start Restoring this baby as soon as possible!!! I do not want to change the crossfire I am planning on keeping the motor its self-looking as stock as possible but i will be putting a better Cam in it and probably Port the intake manifold and few other things.
Burning Brakes
Joined: Sep 2017
Posts: 922
Likes: 163
I bought a 1984 C4 before winter started and now its springtime, I am ready to start working on it. My problem right now is I want to pull it in and out of my garage, but I am afraid that breaks will let go and I will drive right thought the wall. I have a high idle of roughly 3k and roughly 2k when I put it in gear. The car has 33k miles on it. What parts should I buy to fix this problem or what can I do to solve the problem. I am assuming its 1 of 2 things or maybe both. please let me know a solution so I can't start Restoring this baby as soon as possible!!! I do not want to change the crossfire I am planning on keeping the motor its self-looking as stock as possible but i will be putting a better Cam in it and probably Port the intake manifold and few other things.
Le Mans Master
Joined: Aug 2017
Posts: 6,930
Likes: 1,487
From: New Jersey
I'd also check the throttle position sensor, I had one fail closed and the ECM recognized it as 100% throttle and caused all sorts of weird issues. If you back probe the sensor on pins A and B you should see about .525 volts DC, key in run, throttle closed. It should increase to near 5 volts as you open the throttle and be fairly smooth. Pin A should be ground and pin C should be reference. Pin B is the ECM signal which voltage should vary on. The pins are in alphabetical order so A is the lower pin when looking at the TPS and C is the upper one. It is a simple enough check if vacuum testing comes back fine. Also, confirm the throttle blades are actually fully returning as well.
